Combined trailer hitch and brake control means



July 12, 1949. L. R. SYMMONDS 2,476,003

COMBINED TRAILER HITCH AND BRAKE CONTROL MEANS Filed Jan. so, 1946Patented July 12, 1949 "ICOMBINED"T RAILER HITCH AND BRAKE "GO'NTROLMEANS Jmyal. R. :Symmonda-Fresno, Calif.

Application January '30, 1946, Serial N0.6i4,366

Whis' invention relates primarily to a trailer hitch 'oi thedetachabletypecommdnlwus'ed in towing "relatively smalb trailers suchashouse trailers,- boir trailers, =and 'the like atthe' rear ofautomobiles-such aspassen'ger cars; light trucks, etc:, and it has' foritsprime objecttheprovision of a device of" the "abovecharacter'soconstructed and arranged as to he operated by the backlash betweer r'thetowing vehicle and trailer to auto matically'control the brakes of'thetrailer.

Another-object is to provide a' combined trailer hitch'an'd" brakecontrol" means whichrcan be easily-andqu'ickly permanently positionedupon a trailer and' easily and quicklyconnectedto or disconnected froma'towing vehicle withoutdisturbin'g its-'position 'upomthe trailer.

'Anothefobject is to*'provide"in a device of the above' character means-foreasily 'and quickly adjusting the"sameto"vafryingloads carried bythe trailer.

Other-objectsand'advantages appear hereinafter and while I haveshown andwill describe the preferred formof'my'invention, it will be understoodthat Ludo-not; limit-:myself to such preferred form but that variouschanges and adaptations may be made therein without departing from thespirit of my invention.

In the drawingsaccompanying. "and" forming a part hereof:

Fig; L is a side elevationrpartly. in section, of my-device'detached"irom'its 'place of use.

" "Fig; 2 is a ieft handel'evationofFig. 1.

-*Figi 3 is a sideeievation'on a reduced scale showing my device andsufficient of a trailer and towing vehicle to illustrate its applicationthereto.

Fig. 4 is a view of the means used to render my braking meansinoperative.

Referring to the drawings my device comprises a cylinder 5 provided withoppositely disposed external Wings or flanges 6 and I by means of whichthe same is secured to the drawbar 8 of the trailer (not shown), bybolts 9 or otherwise.

Projecting forwardly from one end of cylinder 5, concentric therewith,is an integral tubular sleeve [0.

Formed within cylinder 5 is a piston chamber II the open end of which isnormally closed by a screwthreaded cylinder head l2.

Slidably mounted within chamber II is a piston I 3 provided with atubular stem [4 which projects slidably through sleeve It! to extend fora distance beyond the end of the same, and adjustably mounted upon thisprojecting end is a collar l5 which provides a means for limiting C '4Claims. (Cl. 188e-142) 2 the'relative movement of said piston andicylineder as hereafter explained.

Mounted within 'the chamber ll to:*extend between the piston l3 and thecylinder'head I2 is a coil spring'lt which acts to resist themovement-of piston 53 relative to cylinder 5.

- Ecrewthreadedly mounted at one of their ends inrthe front or closedend of. cylinder 5 to'project loosely through piston l3 and into chamberii, are oppositely disposed studsl'l and i8 the free ends of which areconnected by a bar l9 centrally of the length of which is provided aboss 20. The free ends of studs l1 andIB are screwthreaded and providedwith nuts H and 22.

Provided within the piston stem 14 is a piston chamber 2! in which isslidably mounted a piston 22 detachably mountedupon a hollow tubularstem 23 the other end of which is rigidly mounted within the boss 20 ofbarl9.

Provided thru the upper wall of sleeve 10 is an elongated aperture 24and extending thru this: apertureeQA is the outlet stem 25- of the fluidI'GSSIVOHYK'ZB thewlowerend of'whicnis rigidly mounted in the adjacentWall of piston stem '1 l. Ancoutletzpassag"2i'connects'the interior ofreservoir 2t" with-tthe interior of" piston chamber 2|.

A fillingnozzlez28=normally closed-by aiplug 29 provides means for.replenishing the fluid supply in .IS6IV10lr" 25.

.The wheels of. the trailer will be equipped'with any of the wel l.knownoncommonly used hydraulic brakermechanisms (l'l.0tx.ShOW1'1)iithB'master cylinder of which will be connected by a tube 30 extendingtherefrom to the end of the hollow piston stem 23 within the pistonchamber ll, thus connecting the same to the piston or pressure chamber2|.

In use, the forward or projecting end of stem M will be connected to thebumper or other portion 32 of the towing vehicle by any of the commonlyused ball and socket connections 33 and the cylinder will be connectedto the drawbar 8 of the trailer by means of flanges 6 and I and bolts 9.

In operation the parts will normally lie in the positions shown and willso remain as long as the towing vehicle exerts a pull or tension uponthe stem I4. Any variation of the relative speed of the vehicles tendingto lessen the distance therebetween will cause the stem M to moverearwardly against the tension of spring l6 and in the event thepressure is sufficiently great to compress said spring materially andcause piston l3 and stem I4 to move rearwardly relative to cylinder 5piston 22 will move in the opposite direction across the outlet 21 ofthe fluid reservoir and exert pressure upon the fluid in chamber 2! outthru hollow stem 23 and tube 30 to the hydraulic braking system of thetrailer and operate the same to retard forward movement of the trailer.

It will be understood of course that a supply of hydraulic fluid willhave previously positioned in the system with a reserve supply inreservoir 26.

In the event it becomes necessary or desirable to render the brakingmeans inoperative such as when backing the vehicles, I provide asubstantially inverted U-shaped member 36 adapted to be positioned uponthe sleeve I4 between collar 55 and the end of sleeve Ill wherebyrelative movement of said sleeves will be prevented and the devicerendered inoperative.

By adjusting the position of the cylinder head l2 relative to thecylinder 5 the tension of spring It may be increased or decreased toaccommo= date various weights of the load being towed. Having describedmy invention what I claim is:

1. In a device of the character described a cylindrical body memberhaving a piston chamber at one end and a bearing sleeve at its otherend; a piston in said piston chamber having a reduced concentric tubularstem projecting thru said sleeve in slidable engagement therewith; anjustable collar surrounding the free end oi said stem; a pressurechamber in said stem; a in said pressure chamber having a hollow stenextending through said first piston chamber adapted for connection tothe brake operating mechanism of a trailer; a connection said last stemto said body member for causing the to move in unison; a fluid supplytank for said pressure chamber; a fluid passage iron. said to saidpressure chamber; and a coil spring in said first piston chamber betweenthe piston and the rear wall thereof.

2. In a device of the character described a housing having a pistonchamber at one end and a bearing sleeve at its other end, said pistonchamber having a closed outer end; a piston in said piston chamberhaving a tubular stem extending thru said bearing sleeve slidabletherein; an adjustable collar on the free end of said stem; a pressurechamber in said stem; a piston in said pressure chamber; a fluidreservoir in communication with said pressure chamber; a hollow stem forsaid last piston in communication with said pressure chamber at one endand having its other end adapted to be connected to the braking systemof the trailer; a connection from said last stem to said housing forpreventing relative movement therebetween; and a resilient means in saidfirst piston chamber for resisting relative movement between saidhousing and said piston.

3. A device of the character described comprising a housing having apiston chamber in one end and a bearing sleeve at its other end; apiston in said piston chamber having a tubular stem extending thru saidbearing sleeve slidable therein; a pressure chamber in said stem; apiston in said pressure chamber having a hollow stem in communicationwith said pressure chamber at one end and connected at its other end tothe braking system of the trailer; adjustable means connecting said laststem and said housing for preventing relative movement therebetween; 1resilient means in said first piston chamber for resisting relativemovement between said piston and housing; a fluid reservoir incommunication with said pressure chamber; and means for varying theresistance of said resilient means.

4. A device of the character described comprising a housing having apiston chamber in one end and a bearing sleeve at its other end; apiston in said piston chamber having a tubular stem extending thru saidbearing sleeve slidable therein; a pressure chamber in said stem; apiston in said pressure chamber having a hollow stem in communicationwith said pressure chamber at one end and connected at its other end tothe braking system of the trailer; adjustable means connecting said laststem and said housing for preventing relative movement therebetween;resilient means in said first piston chamber for resisting relativemovement between said piston and housing; a fluid reservoir incommunication with said pressure chamber; and means for varying theresistance of said resilient means;

and a detachable connection from the free end of said sleeve and atowing vehicle.

LOYAL R. SYMMONDS. REFERENCES CITED The following references are ofrecord in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,149,189 Shafier Feb. 28, 19392,162,029 Paul June 13, 1939 2,401,084 Laudahl May' 28, 1946

